1. Field of the Invention
The present invention relates to an intravascular catheter provided with a function for controlling the blood flow.
2. Description of the Related Art
Insertion of an intravascular catheter in a blood vessel can be confirmed by flashback, that is, the backward flow of the blood at the time of piercing the intravascular catheter into the blood vessel. However, a problem of leakage of the blood flowing backward arises at the time of pulling out the internal needle. In order to cope with the problem, conventionally, a method of stopping the blood by pressing the tip end part or the hub base part of the intravascular catheter, a method of preventing the blood leakage by providing an elastic tube at the catheter base end part and pressing the tube part with a finger at the time of pulling out the internal needle, and a method of preventing blood leakage by storing an elastic tube with a swelling in the catheter base end part and pressing the swelling part (U.S. Pat. No. 3,856,010) have been proposed. FIGS. 25 and 26, show the conventional method of restraining the leakage by directly pressuring the catheter part outer surface in the vicinity of the hub base of the intravascular needle with a finger. However, since the method of directly pressuring the catheter outer surface is a method of closing the catheter itself by flattening the same with the pressure, there is a risk of breaking the catheter itself by the flattening operation so as to lead to cut-off of the catheter. Moreover, intravascular catheters comprising a means for directly pressing and closing the catheter base end part outer surface (U.S. Pat. Nos. 5,108,374 and 5,542,933) have been proposed, but since the catheter part is pressured directly in these methods, catheter breakage may be brought about.
Furthermore, since the above-mentioned methods involve the pressure from above so as to apply the pressuring force to the vicinity of the insertion part, the blood vessel, and the skin of the patient, a problem is involved in that the patient suffers the great pain.
As a means for preventing the blood leakage without giving a pain to the patient, a method of providing a blood flow controlling device such as a check valve, a detent plug, and forceps stoppage in an elastic tube part can be presented. Examples of the methods include a method of further providing an elastic clamp tube part between a hub part at the catheter base end part and a connector part as a part for connecting with an external circuit so as to enable closure with forceps (JP-B-61-25490U, JP-B-6-39724U) . However, in the case of using a tool such as metal forceps, since the elastic clamp tube is fixed firmly by clamping, there is a risk of ruining the elastic clamp tube part to cause breakage as in the above-mentioned methods so as to lead to leakage of the blood or the transfusion liquid. Moreover, since the forceps are bulky, the hand can be uncertain so that the safe and certain operation may be prevented. Furthermore, there is a risk of fall-off of the inserted catheter due to self weight of the forceps when the operator leaves the hand. Moreover, since the method requires the elastic clamp tube part between the hub part and the connector part, the number of parts is increased so that the production and assembly is complicated as well as the equipment cost is increased as well. Furthermore, since the length of the hub part and the connector part is prolonged for the clamp tube, a problem is involved in that the operativity and the handling convenience are deteriorated due to the bulkiness.
As a means for preventing the blood leakage without using forceps, a method of providing wing parts between the hub and the connector, and nipping the wings of both sides so as to pressure and close the elastic tube (JP-B-1-15308, JP-A8-141078, JP-W-9-509075) has been proposed. However, also in the method, the problems are not solved such as increase in the number of parts due to necessity of the elastic tube part between the hub part and the connector part, complication of the production and assembly so as to increase the equipment cost, and prolongation of the hub part and the connector part so as to cause bulkiness and operation difficulty.
As another problem, since the method of pressuring the catheter part with a finger, and the method of pressuring and closing by wings require the holding or nipping operation with one hand for fixing and maintaining the pressured state, there is a risk of inadvertent piercing by the internal needle after pulling off, or connection mistake at the time of connecting the circuit due to insufficient attentiveness.
In view of the above-mentioned circumstances, an object of the invention is to provide an intravascular catheter capable of closing the catheter part without breaking the catheter part by pressuring the catheter part via a flexible resin member provided on the outer surface of a catheter part, and further comprising a blood leakage prevention member capable of preventing the blood leakage.
Moreover, another object is to provide an intravascular catheter comprising a mechanism for easily fixing or releasing the state with the blood leakage prevented by pressuring and closing the catheter.
The invention can be realized by the following means.
A first aspect is an intravascular catheter comprising a catheter part; an internal needle disposed through the catheter part; and a flexible resin member disposed on the outer surface of the catheter part.
A second aspect is the intravascular catheter according to the first aspect, comprising a blood leakage prevention member for preventing leakage of blood by closing the catheter part via the flexible resin member.
A third aspect is the intravascular catheter according to the second aspect, wherein the blood leakage prevention member comprises a pressure part capable of pressuring the catheter part via the flexible resin member.
A fourth aspect is the intravascular catheter according to the third aspect, wherein the blood leakage prevention member comprises a fixing mechanism capable of fixing the pressure part in the pressuring state.
A fifth aspect is the intravascular catheter according to the fourth aspect, wherein the blood leakage prevention member comprises a releasing mechanism capable of releasing the pressuring state of the pressure part.
A sixth aspect is the intravascular catheter according to the second aspect, wherein the blood leakage prevention member comprises wing parts disposed on the right and left sides with respect to the axial direction of the catheter part.
A seventh aspect is the intravascular catheter according to the sixth aspect, wherein the wing parts are provided integrally with at least one of a pressure part capable of pressuring the catheter part via the flexible resin member, a fixing mechanism capable of fixing the pressure part in the pressuring state, and a releasing mechanism capable of releasing the pressuring state of the pressure part.
An eighth aspect is the intravascular catheter according to the seventh aspect, wherein the fixing mechanism is a nail part provided on at least one of the right and left wings, to be fixed by engagement with the other side wing part.
A ninth aspect is the intravascular catheter according to the seventh aspect, wherein the fixing mechanism is a nail part provided on at least one of the right and left wings, and the fixed state by engagement with the other side wing part is capable of being released.
A tenth aspect is the intravascular catheter according to the seventh aspect, wherein the fixing mechanism is a pair of projection and recess fitting parts provided each on the right and left wings, to be fixed by engagement of the projection and recess of the fitting parts.
An eleventh aspect is the intravascular catheter according to the seventh aspect, wherein the fixing mechanism achieves fixation according to engagement of the right and left wings such that one of them covers the other.
A twelfth aspect is the intravascular catheter according to the eleventh aspect, wherein the fixed state can be released by releasing the fixing mechanism according to the force from the outer direction applied by nipping both of the right and left wings in the fixed state.
A thirteenth aspect is the intravascular catheter according to the first aspect, wherein the flexible resin member is formed integrally with at least one of the catheter part and a connector part provided on the base end part of the flexible resin member.
A fourteenth aspect is the intravascular catheter according to the first aspect, wherein the catheter part and the flexible resin member are fixed by one of welding, fusion and an adhesive.
A fifteenth aspect is the intravascular catheter according to the first aspect, wherein the flexible resin member is a thermally contractible member, fixed on the catheter part outer surface by thermal contraction.
A sixteenth aspect is the intravascular catheter according to the first aspect, wherein a hub part is provided on the base end side of the flexible resin member.
A seventeenth aspect is the intravascular catheter according to the first aspect, wherein the flexible resin member has a pipe-like shape, whose cross-sectional shape has the ratio A/B of the thickest thick part A and the thinnest thick part B in the range between 1 and 10.
An eighteenth aspect is the intravascular catheter according to the first aspect, wherein the flexible resin member has a pipe-like shape, with an elliptical cross-sectional shape with the ratio C/D of the longer axis C and the shorter axis D in the range between 1 and 4.